Process of detinning.



lllrviThn STATES FRANZ VON KllGELGEN AND GEORGE O. SEWARI), OF HOLUOMBS ROCK,

Patented. February 2d, 1905.

PATENT Urrrce.

VIRGINIA, ASSIGNORS TO THE l VILLSON ALUMINUM COMPANY, OF NEl V YORK, N. Y., A COIRPORA'IION OF NEW YORK.

PldUCllE$$ 0f UETlNNINGL SPECIFICATION forming part of Letters Patent No. 783,726, dated February 28, 1905.

Application filed August 1, 190 Serial No. 219,052. I

To In wlmnt if; 'nuty concern: 7

se it known that we, FRANZ VON Ktfreunenu, a su bject of the German Emperor, and Gnonee S EWARD, a citizen of the United States, both residing at Holcombs Rock, in the county of Bedford and State of Virginia, have jointly invented certain new and useful Improvements in Processes of Detinning, of which the following is a specification.

This invention aims to economically separate tin from other metals, such" as the iron in tin-scrap, and provides certainimprovements over the process described in our application, Serial No. 189,272, filed January 16, 1904.

in the process of this invention a solution of dry chlorin in a liquid which contains no moisture is used. In the very limited use of chlorin in metallurgical establishments hitherto for the extraction of metals the chlorin has been generally used in a wet state. Such processes have the drawback that almost all metals are attacked by wet chlorin. A separation of the metals is therefore impossible. For example, in detinning operations wet chlorin would not be practically useful, as together with the tin considerable amounts of iron would also be attacked. Dry chlorin, however, between certain limits of temperature acts on tin, but not on iron, and the application of this principle is the basis of our previous application above referred to. We have now discovered that a solution of the dry chlorin in stannic chlorid or other suitable anhydrousliquid removes the tin with a most astonishing completeness and rapidity. A piece of tin-scrap dropped into such a solntion is detinnecl almost instantly, the iron being notattacked at all. Liquid stannicchlorid chlorid.

1 out where other metals are found in the tin scrap, as the anhydrous stannic chlorid does not dissolve other chlorids. The stannic chlorid containing the dry chlorin gas in solution attacks the tin, forming more stannic chlorid, and thus adding to the quantity originally in use.

The process in detail, for example, may be carried out as follows: Tin-scrap is placed in a closed. vessel, so as to prevent moisture reaching the materials, and is there subjected. to a solution of dry chlorin in anhydrous stannic chlorid. There should always be pres out a suiiicient quantity of dissolved chlorin to form an excess above the amount necessary to convert the tin into stannic chlorid. After the chlorination has taken place the stannic chlorid or a part of it may be regenerated by the addition of a suitable quantity of fresh dry chlorin, so that it may be used again. Thus the same quantity of stannic chlorid may be used repeatedly, taking away after each operation the quantity of new stannic chlorid formed. The stannic chlorid removed may then be treated for the recovery of the metal tin by electrolysis or by chemical or other suitable process.

Various other methods of manipulation of the materials may be used. Though stannic chlorid is preferable for the reasons above stated, yet any other liquid might be used which is capable of dissolving dry chlorin and which contains no moisture.

Though we have described with great particularity of detail a process embodying the invention, yet it is not to be understood therefrom that the invention is limited to the specific embodiment disclosed. Various modifications may be made by theses-killed in the art without departure from the iurei'ition.

What we claim is---- l. The process of detinniug which consists in subjecting the tinned metal to the action of an anhydrous liquid containing dry chlorin.

2. The process of detinning which consists in subjecting the tinned metal to the action of In witness whereof we have hereunto signed IO anhydrous-liquid stannic chlorid containing our names 1n the presence of two subscribing dissolved dry ehlorin. witnesses.

3. lhe process of detinning which consists FRANZ VON KUGELGEN 5 1n sub ecting the tlnned metal to the action 0t GEOPGE O SEVARD anhydrous-liquid stannic chlorid containing 1 dissolved dry ohlorin in exoess of the amount \Vitnesses:

necessary to convert the tin into stannic J NO. B. HUFFARD,

chlorid. E. F. SCALES, Jr. 

